Satellite integrity monitoring with crowdsourced mobile device data

ABSTRACT

Disclosed are a system, apparatus, and method for monitoring integrity of satellites, and global navigation satellite systems (GNSS). One or more satellites in one or more GNSS are monitored based on a reference crowdsourced integrity report. One or more satellite integrity metrics are determined for the one or more satellites based at least on signals from the one or more satellites. A position of the mobile device is estimated. The position of the mobile device and the one or more satellite integrity metrics are provided.

FIELD

The subject matter disclosed herein relates generally to monitoringintegrity of individual satellite vehicles and constellations, and morespecifically to monitoring with crowdsourced mobile device data.

BACKGROUND

Mobile devices such as consumer mobile phones often have integratedglobal navigation satellite system (GNSS) based positioning features toassist users in determining geographic location. To determine locationfrom GNSS typically consists of receiving GNSS measurements and datafrom one or more of GNSS satellite constellation systems (e.g., GlobalPositioning System (GPS), Globalnaya Navigazionnaya Sputnikovaya Sistema(GLONASS), BeiDou, Quasi-Zenith Satellite System (QZSS), and Galileo).Some GNSS constellations may be more error prone than others, howevereven the most accurate GNSS constellations may have an errant satellitevehicle (SV) which may degrade the positioning performance when utilizedby a mobile device. Therefore, it is advantageous to improve GNSSpositioning for a high quality user experience on mobile devices.

BRIEF SUMMARY

Some embodiments discussed herein provide for a mobile device to utilizecrowdsourced data to verify the integrity of one or more GNSS satellitevehicles (SVs) and/or a GNSS constellation.

In one aspect, a method for a mobile device to monitor satelliteintegrity is described, the method comprising: obtaining one or moresatellites in one or more GNSS to monitor based on a referencecrowdsourced integrity report; determining, at the mobile device, one ormore satellite integrity metrics for the one or more satellites based atleast on signals from the one or more satellites; estimating a positionof the mobile device; and providing the position of the mobile deviceand the one or more satellite integrity metrics.

In yet another aspect, a device to monitor satellite integrity, thedevice comprising: memory; and a processor coupled to the memory and theprocessor is configured to: obtain one or more satellites in one or moreGNSS to monitor based on a reference crowdsourced integrity report;determine, at the mobile device, one or more satellite integrity metricsfor the one or more satellites based at least on signals from the one ormore satellites; estimate a position of the mobile device; and providethe position of the mobile device and the one or more satelliteintegrity metrics.

In a further aspect, a machine readable non-transitory storage mediumhas stored therein program instructions that are executable by aprocessor to: obtain one or more satellites in one or more GNSS tomonitor based on a reference crowdsourced integrity report; determine,at the mobile device, one or more satellite integrity metrics for theone or more satellites based at least on signals from the one or moresatellites; estimate a position of the mobile device; and provide theposition of the mobile device and the one or more satellite integritymetrics.

In a further aspect, an apparatus to verify satellite integritycomprises: means for obtaining one or more satellites in one or moreGNSS to monitor based on a reference crowdsourced integrity report;means for determining, at the mobile device, one or more satelliteintegrity metrics for the one or more satellites based at least onsignals from the one or more satellites; means for estimating a positionof the mobile device; and means for providing the position of the mobiledevice and the one or more satellite integrity metrics.

The above and other aspects, objects, and features of the presentdisclosure will become apparent from the following description ofvarious embodiments, given in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communications operating environment forimplementing SV Integrity Monitoring, in one embodiment.

FIG. 2 is a flow diagram of a method for SV Integrity Monitoringimplemented by a mobile device, in one embodiment.

FIG. 3 is a flow diagram of a method for SV Integrity Monitoringimplemented by a server, in one embodiment.

FIG. 4 illustrates an exemplary device to perform SV IntegrityMonitoring.

DETAILED DESCRIPTION

The word “exemplary” or “example” is used herein to mean “serving as anexample, instance, or illustration.” Any aspect or embodiment describedherein as “exemplary” or as an “example” is not necessarily to beconstrued as preferred or advantageous over other aspects orembodiments.

In one embodiment, commodity mobile devices as part of a crowdsourcedsystem provides Satellite Vehicle (SV) Integrity Monitoring (referred toherein simply as SVIM) for a single satellite and/or for a constellationof satellite vehicles. In some embodiments, SVIM may be implemented in acrowdsourced system to verify the integrity of a satellite vehicle andGNSS constellation so sub-standard measurements and data can be avoidedor the impact of problematic SV within a GNSS can be mitigated. In oneembodiment, aspects of SVIM are implemented on a mobile device and/or aserver to retrieve SVIM data from a field of crowdsourced mobiledevices. For example, a mobile device may monitor a SV and/or aconstellation of SVs and determine integrity metrics for particular SVsand/or the constellation. The integrity metrics may be provided to aserver (e.g., in an integrity metric dataset or other datapackage/arrangement). In one embodiment, the server (e.g., a servercapable of performing aspects of SVIM described herein) combines one ormore aspects of the integrity metrics provided by the mobile device. Inone embodiment, as a result of combining the crowdsourced integritymetrics from multiple individual mobile device sources, the server (orservers) can create/update a reference crowdsourced integrity reportwhich may be used by mobile devices to optimize theirpositioning/location determination.

In some embodiments, SVIM as described here is used in addition to orinstead of expensive specialized reference networks. For example, a GNSSintegrity monitoring system may be built with dedicated worldwidereference networks, operating with dedicated fixed position referencesites. These dedicated non-mobile reference sites may utilize expensivestationary geodetic grade reference receivers, antennas, communicationequipment, and one or more network processing centers. These networksand associated services may provide various atmospheric, orbitalcorrections and integrity monitoring to subscribers, however often atsignificant cost due to the expense of the stationary installations andthe complexity of operating the sites.

FIG. 1 illustrates a wireless communications operating environment forperforming SVIM, in one embodiment. In one embodiment, a SVIM system(e.g., FIG. 1 operating environment 100) includes a one or more mobiledevices (e.g., mobile devices 105) which monitor one or more satellitevehicles (e.g., SVs 110) within a constellation (e.g., constellation115). Mobile devices 105 may monitor one or more SVs 110 and reportintegrity metrics to other devices (e.g., to one or more of the field ofmobile devices 105) or a server (e.g., server 120 which may beimplemented with one or more aspects of SVIM) to determine a referencecrowdsourced integrity report. In some embodiments, mobile devices 105may create or update a reference crowdsourced integrity report locallyat the device and send to server 120 or other mobile devices 105. In oneembodiment, server 120 may retrieve monitoring data (e.g., integritymetrics such as integrity metrics in a dataset or other data package) orreference crowdsourced integrity reports from devices 105 andconsolidate or combine known integrity data. In one embodiment, server120 creates or updates a reference crowdsourced integrity report fromthe combined integrity data of multiple sources. The updated referencecrowdsourced integrity report may be made available to mobile devices105 so that mobile devices may achieve optimized positioning or locationdetermination by avoiding or adjusting data from one or more SVs orconstellations with questionable integrity. In some embodiments, server120 maintains a crowdsourced GNSS integrity database 140 from the manymobile devices reporting integrity metrics. In some embodiments,crowdsourced GNSS integrity database 140 may be a separate device fromserver 120 or may be integrated into server 120.

In one embodiment, mobile devices within a crowdsourced environmentprovide integrity metrics to server 120 such that the integrity datafrom many sources can be used to determine particular problem areas(e.g., SV or constellations of questionable/suspect integrity). In someembodiments, a SVIM capable server combines the multiple incomingintegrity metrics (e.g., multiple datasets from the same mobile device,and/or multiple datasets from multiple unique mobile devices) to createor update a reference crowdsourced integrity report (i.e., a globalintegrity report for a particular SV, constellation or GNSS). In oneembodiment, a SVIM server receives updated integrity reports from afield of mobile devices each performing particular integrity monitoring.

In some embodiments a SVIM server or mobile device may manage the fieldof crowdsourced mobile devices to direct monitoring to particular SVs,constellations, geographic area, and/or data types. For example, a SVIMserver may determine a particular SV or constellation has limited datapoints for establishing integrity and may actively request additionalintegrity metrics for that particular SV. In some embodiments, a SVIMserver can determine a particular geographic area is relatively sparselypopulated by integrity metrics and may actively request mobile deviceswithin the area to provide one or more particular metrics. In someembodiments, the server may prune its integrity data based on time ofacquiring the data. For example, integrity data may age at the serversuch that after a configurable amount of time has passed, the data maynot be as reliable as newly acquired integrity data. In someembodiments, the server simply deletes old data, or may mark older datawith a reduced confidence or reliability tag.

The server can combine reports to update the crowdsourced integrityreport and can update mobile devices 105 as new data is determined.Therefore, integrity of individual SV and overall constellationintegrity can be maintained by leveraging many inexpensive crowdsourceddevices in a network. Data from mobile devices may be constantlyprovided to the server as mobile devices traverse particular geographiclocations such that the server may have a nearly constant stream ofintegrity monitoring to process and analyze. In some embodiments, theserver may produce updated reference crowdsourced integrity reports atset intervals, when incoming data meets a threshold, or otherconfigurable parameter. In some embodiments a server may be manuallytriggered (e.g., by a server administrator) to update the referencecrowdsourced integrity reports from available (i.e., received)crowdsourced integrity metrics stored at the server. In someembodiments, a particular event or condition may cause the server toupdate its reports. For example, if a new mobile software version isrequested, if there is a known change in SV or constellationconfigurations, or other events.

In some embodiments, system 100 includes access points 130 (APs) withina Wireless Local Area Network (WLAN) and some of the AP 130 and BTS(Base Transceiver Station or wireless wide area network (WWAN) 135) maycommunicate with the mobile devices 105. For example, mobile devices 105may send or receive updated integrity reports or integrity metricsto/from server 120 or other mobile devices through AP 130. Server 120may additionally send a request for more or less integrity data to AP130 or BTS 135 for distribution to mobile devices within theirrespective operating range. In some embodiments, mobile device 105determines an initial position estimate utilizing on or more of AP 130or BTS 135. In some embodiments, the position from AP 130 or BTS 135 maybe used to verify position determined from constellation 115.Differences in position estimates from varying sources may be includedin integrity metrics provided by mobile devices 105.

Mobile devices 105 may be dispersed throughout the wirelesscommunications system 100. Mobile device 105 may also be referred to bythose skilled in the art as a mobile station, a subscriber station, amobile unit, a subscriber unit, a wireless unit, a remote unit, awireless device, a wireless communication device, a remote device, amobile subscriber station, an access terminal, a mobile terminal, awireless terminal, a remote terminal, a handset, a user agent, a mobileclient, a client, or some other suitable terminology. Mobile device 105may be a cellular phone, a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a tabletcomputer, a laptop computer, a cordless phone, a wearable item such as awatch or glasses, a wireless local loop (WLL) station, or the like.Mobile device 105 may be able to communicate over different accessnetworks, such as cellular, Wireless Wide Area Network (WWAN), orWireless Local Area Network (WLAN).

The communication links 125 shown in system 100 may include uplinks forcarrying uplink or downlink transmissions (e.g., from mobile device 105to a BTS 135). The communication links 125 shown in system 100 may alsoinclude signals received/monitored from SV 110 used in determiningintegrity metrics. For example, the navigation data broadcasted by asatellite can also be sent to a mobile through a ground communicationnetwork. In some embodiments, mobile device 105 can determine positionbased on mobile sensors, network, or mobile based positioning inaddition to or instead of GNSS based positioning using SV 110.

In one embodiment, mobile devices within a SVIM system collect integritymetrics (e.g., measurement data) associated with a one or moreparticular satellite vehicle (e.g., SV 110 in a GNSS). In someembodiments, integrity measurement data may also be acquired from awireless wide area network (e.g., WWAN 135), WiFi Access Points (e.g.,AP 130), Micro-Electro-Mechanical Systems (MEMS), and other systems inaddition to or instead of SV data. Integrity metrics collection (e.g.,from monitoring one or more SVs) may occur in a constantly updatingand/or recursive basis for one or more available mobile devices 105 inthe SVIM system. The crowdsourced mobile devices 105 may be capable toperform multiple GNSS and hybrid position, velocity and time (PVT)calculations.

Integrity monitoring may occur locally at each device and also integritymonitoring data may be transferred between peers/servers within the SVIMsystem (e.g., to other mobile devices 105 and/or server(s) 120). In someembodiments, in response to or while performing PVT computations, themobile system may perform computations for checking and addressing theintegrity of GNSS data. For example SVIM can detect outliers and biasesin over the air broadcast navigation parameters, signal quality,predicted and network assistance data (e.g., in the case of AssistedGNSS) and may make decisions about flagging, excluding SVs orconstellations and taking corrective action in PVT computations. In oneembodiment, the quantity and quality of the crowdsourced GNSS integritymonitoring data from a large number of worldwide mobile devices canprovide a flexible and extensive warning or control mechanism.

In one embodiment, reference crowdsourced integrity reports can indicatewhich particular SVs, constellations, or geographic areas are of highintegrity (i.e., operating within expected parameters). A mobile devicemay determine on a case by case basis or by a configurationsetting/parameter how particular SVs, constellations, or geographicareas which have low integrity should be treated when performing GNSSbased positioning. For example, low integrity components may beeffectively offline or otherwise blacklisted from usage with mobile GNSSbased positioning (e.g., low integrity rating is below a configurablethreshold). For example, a particular SV or constellation may havereceived error reports from crowdsourced mobile devices to a greatenough extent that mobile devices should be advised to disregard theirsignals when calculating GNSS based positioning. In some embodiments,certain geographic areas may be classified as more error prone due tosome particular local interference specific to that area and the mobiledevice may have more accurate positioning results using alternativemethods of positioning. For example, a geographic area, SV, orconstellation may be actively jammed or subject to deliberateinterference by hostile parties.

In some embodiments, reference crowdsourced integrity reports caninclude time sensitive integrity reports such that a mobile device iswarned for using GNSS with a particular geographic area, SV, orconstellation during particular time windows. For example, crowdsourcedintegrity metrics may detect a historical pattern of interference (e.g.,a power plant may cause interference during certain times of operation)for which mobile devices may chose to switch to alternatives to one ormore components of GNSS based positioning during a particularlytroublesome time window.

Crowdsourcing of integrity monitoring using mobile devices (e.g.,consumer mobile phones) can be a cheaper and more robust alternative todeploy for integrity monitoring and integrity assurance compared tooperating a reference network with limited number of expensive andcostly to maintain stationary reference stations.

In one embodiment, monitoring integrity of SV and constellations mayinclude determining WLS (Weighed Least Squares) estimation RAIM(Receiver Autonomous Integrity Monitoring). For example, identifying andisolating faulty satellites or constellation by detecting rangingoutliers in the measurements.

In one embodiment, monitoring integrity of SV and constellations mayinclude KF (Kalman Filter) estimation RAIM. For example, checking thepredicted measurements based KF states versus actual measurements.

In one embodiment, monitoring integrity of SV and constellations mayinclude comparing WLS to KF and checking the result of the comparisonwith known or expected results/ranged. For example, comparing PVTsolutions from WLS estimator and KF estimator (above).

In one embodiment, monitoring integrity of SV and constellations mayinclude Cross-Kalman Filters checking (multiple filters runningconcurrently). For example, checking multiple/concurrent KF filtersagainst each other.

In one embodiment, monitoring integrity of SV and constellations mayinclude SV State (orbit and clock) validation. For example, satelliteorbit and clock validation based on multiple sources.

In one embodiment, monitoring integrity of SV and constellations mayinclude navigation data cross-checks (across different sources ofnavigation data: broadcast (for example, over the air decoded SVnavigation messages), predicted (for example server predicted navigationdata/orbital/clock information, network assistance (for example, AGNSSdata/assisted GNSS data).

In one embodiment, monitoring integrity of SV and constellations mayinclude external integrity information processing (periodic retrievaland injection of integrity information from integrity monitoringserver). In some embodiment, multiple servers each provide externalintegrity information. For example, third party integrityinformation/data.

In one embodiment, monitoring integrity of SV and constellations mayinclude an internal comparison of predicted vs. actual measurementacquisition. For example, if actual measurement is outside of apredicted threshold then SV position or clock may not be consistent.

In some embodiments, the one or more integrity metrics from one or moreof the mobile device based SV integrity monitoring techniques includespseudorange metrics between the mobile device and the one or moresatellites. For example pseudo range may be the pseudo distance betweena satellite and a navigation satellite receiver of the mobile device.For positioning the mobile device can determine its range to satellitesas well as the SV positions at time of transmitting. With the SV'sorbital parameters, these SV positions can be calculated for any pointin time. The pseudorange of each satellite may be determined bymultiplying the speed of light by the time the signal has taken from thesatellite to the mobile device. Because of timing errors, the range isreferred to as a “pseudo” range. Pseudorange metrics may include one orboth of actual pseudorange measurements from satellites and/orresiduals.

In some embodiments, the one or more integrity metrics includespseudorange rate metrics between the mobile device and the one or moresatellites. Compared to timing of the SV signal with respect to themobile device internal clock, pseudorange rate includes frequency errorand the contribution from Doppler shifts associated with motion.Pseudorange rate metrics may include one or both of actual pseudorangerate measurements from satellites and/or residuals.

In some embodiments, the one or more integrity metrics includes carrierphase metrics from the one or more satellites, signal strength forreceived satellite signals. The carrier phase metrics includes themeasure of the range between a satellite and mobile device expressed inunits of cycles of the carrier frequency. Carrier phase metrics mayinclude one or both of actual carrier phase measurements from satellitesand/or residuals.

In some embodiments, the one or more integrity metrics includesnavigation messages from the one or more satellites. For example,satellites may receive operating data from a ground control station, andthe data may be sent to the mobile devices as a navigation message. Thenavigation message can provide the mobile device with information toperform positioning. For example, the navigation message may includeephemeris parameters to compute satellite coordinates, time parametersand clock corrections, to compute satellite clock offsets and timeconversions, service parameters with satellite health information toidentify the navigation data set, ionospheric parameters for singlefrequency receivers, and almanacs for determining the position of allsatellites in a constellation.

In some embodiments, the one or more integrity metrics includesdetermination of satellite signal integrity. In one embodiment, thesatellite signal integrity confidence may be a binary value ofconfidence (e.g., yes confident in SV signal integrity, or not confidentin SV signal integrity). In other embodiments, the confidence may bequantitative data, (e.g., percentage such as 100% confidence, 5%confidence etc.) or qualitative data, (e.g., scale such as high, low,medium confidence etc.) representation.

In some embodiments, the one or more integrity metrics includes a uniqueidentifier of the mobile device and/or identifier of the server oridentifier of particular signals, for example such as a universallyunique identifier (UUID) used to identify information in computersystems.

In some embodiments, the one or more integrity metrics includesconfidence rating for one or more other integrity metrics. For example,the confidence of any of the metrics herein (e.g., confidence inaccuracy of the navigation message, pseudorange, pseudorange rate,unique identifier, carrier phase etc.) may have an associated ratingwhich may be implemented in a variety of ways. In one embodiment, theconfidence may be a binary value of confidence of one or more metrics.In other embodiments, the confidence may be quantitative data, (e.g.,percentage such as 100% confidence, 5% confidence etc.) or qualitativedata, (e.g., scale such as high, low, medium confidence etc.)representation.

In some embodiments one or more SVIM aspects described above in FIG. 1are performed by, or is integrated into both a mobile device and server.SVIM may be implemented as software, firmware, hardware, modules, orengines of a mobile device and/or server (e.g., see device hardware 400below with respect to FIG. 4).

FIG. 2 is a flow diagram of a method for a mobile device to monitorsatellite integrity, in one embodiment. At block 205, an embodiment (forexample, the method implemented by a SVIM capable device) obtains one ormore satellites in one or more global navigation satellite systems(GNSS) to monitor based on a reference crowdsourced integrity report.

For example, the reference crowdsourced integrity report may includemultiple SVs within a GNSS or multiple GNSS. The mobile device may referto the reference crowdsourced integrity report to determine whether tomonitor a particular SV or whether to adjust monitoring according tointegrity reported by the reference crowdsourced integrity report. Forexample, the reference crowdsourced integrity report may specify one ormore SV have suspect integrity and the mobile device may monitor suspectSV or may ignore the SV according to a configuration file at the mobiledevice or by user settings. In some embodiments, the referencecrowdsourced integrity report may include adjustments to the way themobile device monitors a particular SV.

In some embodiments the mobile device monitors, at the position of themobile device, unknown/new one or more satellites to capture integritymetrics. For example, the reference crowdsourced integrity report mayinclude a list or description of SV for which other mobile devices havereported integrity to the server. However, in some cases, the mobiledevice may determine that new SV not listed or documented in thereference crowdsourced integrity report should be monitored. In someembodiments, the reference crowdsourced integrity report has a flag orcommand for the mobile device to provide information on SVs not detailedwithin the reference crowdsourced integrity report or for SVs whereintegrity data is minimal or missing for particular SVs.

In one embodiment, the reference crowdsourced integrity report mayinclude integrity determination of one or more satellites,constellations, or geographic areas. In one embodiment, the integritydetermination may be a binary value of integrity for the respectivesatellite. In other embodiments, the integrity may be expressed asquantitative data, e.g. percentage (100% confidence, 5% confidence etc.)or qualitative data, e.g. scale (high, low, medium confidence etc.)representation. In some embodiments, the integrity determination may bedetermined according to processing integrity metrics received from manymobile devices in the crowdsourced network of devices.

In one embodiment, the reference crowdsourced integrity report mayinclude expected reliability of each integrity determination. Forexample, if the integrity determination is from a limited number ofmobile devices, or within a limited time window, the expectedreliability of the particular integrity determination may be lower thanan integrity determination from a large number of unique devices acrossa varied time window. In some embodiments, the quality of the particularmobile device or the geographic area where the metrics were determinedmay also influence the expected reliability.

In one embodiment, the reference crowdsourced integrity report mayinclude expected signal strength of a satellite signal. For example,expected based on reference crowdsourced data or based on what would bean expected general signal strength.

In one embodiment, the reference crowdsourced integrity report mayinclude expected accuracy of a satellite signal. For example, UserRanging Accuracy (URA) from broadcast signals and User Ranging Error(URE) determined actual error.

In one embodiment, the reference crowdsourced integrity report mayinclude time of applicability for one or more aspects of the referencecrowdsourced integrity report. For example, integrity metrics may haveindividual time of applicability, or have a reference time for theentire report such as time since generated, how long to apply, etc.

In one embodiment, the reference crowdsourced integrity report mayinclude geographic area associated with one or more aspects of thereference integrity report. For example, geographic area may bedetermined from a source identifier of the reference crowdsourcedintegrity report, SV, constellation, mobile device, or server.

In one embodiment, the reference crowdsourced integrity report mayinclude any combination of the above described aspects.

At block 215, the embodiment determines, at the mobile device, one ormore satellite integrity metrics for the one or more satellites based atleast on signals from the one or more satellites. In some embodiments,the one or more satellite integrity metrics includes a signal identifierfor the one or more satellites. For example, the signal identifier maybe used by the mobile device to determine the satellite sourceinformation for one or more signals.

At block 210, the embodiment estimates a position of the mobile device.In some embodiments, the estimated position may be a PVT of the mobiledevice. In some embodiments position may also include acceleration ofthe mobile device at a particular moment in time. PVT may be determinedby AP based positioning, mobile sensor dead reckoning or otherpositioning methods in addition to or instead of GNSS based positioning.At block 220, the embodiment provides the position of the mobile deviceand the one or more satellite integrity metrics. In some embodiments,the mobile device automatically sends position and metrics to arespective server for combination and processing. In other embodiments,the mobile device may hold data until a request by a server or othermobile device. In some embodiments, the mobile device selects, accordingto relevance for an updated integrity report, a subsection of thecaptured integrity metrics for inclusion in the integrity metricsprovided to a server or other mobile devices. For example, the mobiledevice may not always send all monitored data for all SVs orconstellations. In some embodiments, the mobile device selectivelymonitors particular metrics or selectively provides data according toserver need or request.

In one embodiment either or both a server and/or the mobile device cancreate or update integrity reports. In one embodiment, creating theupdated integrity report further comprises one or more of: determiningWLS (Weighed Least Squares) estimation of Receiver Autonomous IntegrityMonitoring (RAIM) measurement data from a plurality of devices, KalmanFilter estimation RAIM from the plurality of devices, comparing the WLSestimation to the KF estimation, cross checking with Kalman Filters of aplurality of measurement data filters, fault detection and verificationor release of suspect satellites, cross-checking navigation data acrossa plurality of different sources of navigation data, or any combinationthereof.

In one embodiment the updated integrity report includes an integritydetermination for one or more constellations of satellites. Theintegrity of a particular satellite within a constellation may affectthe overall integrity when utilizing the particular constellation.

In some embodiments, the mobile device receives an updated crowdsourcedintegrity report where the updated crowdsourced integrity report wasupdated (e.g., by the server receiving integrity metrics) according toat least some of the integrity metrics sent to the server. For example,the mobile device may discover integrity anomalies or confirm data that,when received by the server, triggers the server to create an updatedcrowdsourced report. In some embodiments, as a benefit of being part ofthe crowdsourced group of mobile devices providing integrity metrics,the mobile device may receive updated integrity reports. For example,the mobile device may be subscribed to integrity updates from the serveras they are released or in response to changes in reports. In oneembodiment, a device utilizes the updated integrity report for GNSSimproved assisted navigation or positioning. For example, the device mayreceive GNSS positioning data and determine the position of the mobiledevice using the GNSS positioning data. In some embodiments, the devicedetermines a position from the GNSS including the satellite withoutreliance on the integrity report and may adjust the position accordingto the integrity report to provide an adjusted GNSS position of thedevice. The device may use integrity information for a particular SV todetermine how to adjust internal positioning systems of the device. Forexample, if SV “A” is known to be faulty and provide measurements with“X” amount of error the mobile device may attempt to compensate for thefaulty measurements provided by satellite “A”. In another example, themobile device may determine the error for satellite “A” is too great tocompensate for and therefore the mobile device may ignore all data fromthe satellite, such that GNSS location does not rely on satellite “A”for determining mobile device location.

The device may adjust the GNSS positioning data according to the updatedintegrity report for the satellite and determine a current location ofthe device according to the adjusted GNSS positioning data. In someembodiments, for a known bad satellite, a mobile device may disableprecise tracking to save power.

In some embodiments, the mobile device (e.g., device 105 of FIG. 1)receives a reference crowdsourced integrity report from a server (e.g.,server 120 of FIG. 1). In some embodiments, the device sends updatedintegrity reports to the server or other mobile devices in addition toor instead of reference crowdsourced integrity reports. For example, asintroduced above, the mobile device may be able to make updates to alocal integrity report (e.g., either based upon the reference integrityreport or a new local version integrity report) based on observedintegrity metrics. The mobile device may use the locally created/updatedintegrity report for positioning or share the report with otherdevices/servers.

FIG. 3 is a flow diagram of a method for a server to monitor satelliteintegrity. At block 305, the embodiment (e.g., a server in the SVIM)receives integrity metrics and an associated position from a mobiledevice. For example, the integrity metrics and associated position maybe as described above with respect to FIG. 2. The server may receivemultiple integrity metrics (e.g., metrics from individual mobile devicesmay be bundled or otherwise packaged into a dataset such that the servercan associate/tag metrics to a particular source) and associatedpositions from one or more mobile devices in a crowdsourced network.

At block 310, the embodiment combines the integrity metrics and theassociated mobile device position with pre-existing crowdsourcedintegrity metrics and associated positions. For example, old data mayhave less weighting and new data may have greater weight such thatreprocessing all data can generate a new combined result. In someembodiments new data is used for generating the new report for crosschecking with older reports and new reports may have greater ‘age’weighting than old reports. In some embodiments the old and new reportsmay have different regional information and the different regionalinformation may be combined. In some embodiments, pre-existing data maybe a combination of one or more previously received integrity metricsand the associated mobile device positions from one or more other mobiledevices and the server may store this data for combination with newupdated data. Incoming server data may be any combination from new andunique mobile devices and/or from previously known mobile devices.

At block 315, the embodiment creates or updates a crowdsourced integrityreport according to the combined data from block 310. For example, insome embodiments the server receives integrity metrics from theplurality of mobile devices and creates a reference crowdsourcedintegrity report as introduced above with FIG. 2. In some embodiments,one or more servers continuously receive crowdsourced integrity metricsfrom a plurality of mobile devices and update the crowdsourced integritymetrics as new information is received.

In some embodiments, the server receives a third party integrity reportand incorporates the third party integrity data into updatedcrowdsourced integrity reports which may be distributed to mobiledevices within the SVIM system (e.g., system 100 of FIG. 1). In someembodiments, third party integrity reports may be limited to use/not-useflags for satellites. The third party integrity reports may be takeninto account when combining other integrity data. For example, in theprocess of updating the crowdsourced integrity report, the weight orinfluence of use/not-use flags may be adjusted depending on theestimated quality of the third party integrity report compared to allperceived quality of other available integrity data.

FIG. 4 is block diagram illustrating a device to perform SVIM, in oneembodiment. Device 400 may include one or more processors 401 (forexample, a general purpose processor, specialized processor, or digitalsignal processor), a memory 405, I/O controller 425, and networkinterface 410. It should be appreciated that device 400 may also include(not shown) a display, a user interface (I/F) (for example, keyboard,touch-screen, or similar devices), a power device (for example, abattery or power supply), as well as other components typicallyassociated with electronic devices. In some embodiments, device 400 maybe a mobile or non-mobile device, for example device 400 may be a serversuch as server 120 of FIG. 1 or mobile device such as mobile device 105of FIG. 1.

The device 400 may also include a number of device sensors 435 coupledto one or more buses or signal lines further coupled to the processor(s)401. The sensors 435 may include a clock, ambient light sensor (ALS),accelerometer, gyroscope, magnetometer, temperature sensor, barometricpressure sensor, red-green-blue (RGB) color sensor, ultra-violet (UV)sensor, UV-A sensor, UV-B sensor, compass, proximity sensor. Thewireless device may also include a Global Positioning System (GPS) orGNSS receiver 440 which may enable GPS or GNSS measurements in supportof A-GNSS positioning. In some embodiments, multiple cameras areintegrated or accessible to the wireless device. In some embodiments,other sensors may also have multiple versions or types within a singlewireless device.

Memory 405 may be coupled to processor 401 to store instructions (forexample, instructions to perform SVIM) for execution by processor 401.In some embodiments, memory 405 is non-transitory. Memory 405 may alsostore software or firmware instructions (e.g. for one or more programsor modules) to implement embodiments described herein such as SVIMembodiments described in association with FIG. 2, and FIG. 3. Thus, thememory 405 is a processor-readable memory and/or a computer-readablememory that stores software code (programming code, instructions, etc.)configured to cause the processor 401 to perform the functions describedherein. Alternatively, one or more functions of SVIM may be performed inwhole or in part in device hardware (e.g., as implemented in an SVIMmodule 455).

Memory 405 may also store data from integrated or external sensors. Inaddition, memory 405 may store application program interfaces (APIs) forproviding access to one or more features of SVIM as described herein. Insome embodiments, SVIM functionality can be implemented in memory 405.In other embodiments, SVIM functionality can be implemented as a moduleseparate from other elements in the device 400. The SVIM module 455 maybe wholly or partially implemented by other elements illustrated in FIG.4, for example in the processor 401 and/or memory 405, or in one or moreother elements of the device 400.

Network interface 410 may also be coupled to a number of wirelesssubsystems 415 (for example, WLAN 420, Cellular 430, or other networks)to transmit and receive data streams through a wireless antenna system450 to/from a wireless network or through a wired interface for directconnection to networks (for example, the Internet, Ethernet, or otherwireline systems). Wireless subsystems 415 may be connected to antennasystem 450. Antenna system 450 may be connected to GPS or GNSS receiver440 to enable reception of GPS or other GNSS signals by GPS or GNSSreceiver 440. Antenna system 450 may comprise a single antenna, multipleantennas and/or an antenna array and may include antennas dedicated toreceiving and/or transmitting one type of signal (e.g. cellular, WiFi orGNSS signals) and/or may include antennas that are shared fortransmission and/or reception of multiple types of signals. WLANsubsystem 420 may comprise suitable devices, hardware, and/or softwarefor communicating with and/or detecting signals from WiFi APs and/orother wireless devices within a network (e.g. femtocells). In oneaspect, WLAN subsystem 420 may comprise a WiFi (802.11x) communicationsystem suitable for communicating with one or more wireless accesspoints.

Cellular subsystem 430 may include one or more wide area networktransceiver(s) that may be connected to one or more antennas in antennasystem 450. The wide area network transceivers may comprise suitabledevices, hardware, and/or software for communicating with and/ordetecting signals to/from other wireless devices within a network. Inone aspect, the wide area network transceivers may comprise a codedivision multiple access (CDMA) communication system suitable forcommunicating with a CDMA network of wireless base stations; however inother aspects, the wide area network transceivers may supportcommunication with other cellular telephony networks or femtocells, suchas, for example, time division multiple access (TDMA), Long-TermEvolution (LTE), Advanced LTE, Wideband Code Division Multiple Access(WCDMA), Universal Mobile Telecommunications System (UMTS), 4G, orGlobal System for Mobile Communications (GSM). Additionally, any othertype of wireless networking technologies may be supported and used bydevice 400, for example, WiMax (802.16), Ultra Wide Band, ZigBee,wireless USB, etc. In conventional digital cellular networks, positionlocation capability can be provided by various time and/or phasemeasurement techniques. For example, in CDMA networks, one positiondetermination approach used is Advanced Forward Link Trilateration(AFLT). Using AFLT, a server may compute a position for device 400 fromphase measurements made by device 400 of pilot signals transmitted froma plurality of base stations.

In one embodiment, device 400 implemented as a mobile device storesinstructions (for example, within memory 405) executable by processor401 to determine a reference position, receive signals (for example, vianetwork interface 410) from BTSs, and determine mobile device positionbased on signals from the BTSs. Memory 405 may also store instructionsto detect one or more unreliable BTSs based mobile device positioningmeasurement quality based on the plurality of BTSs and/or rangemeasurement quality. Device 400 may also provide (for example, vianetwork interface 410 and wireless subsystem 415) a status reportincluding BTS data and mobile device data.

The device as used herein (for example, device 400) may be a: wirelessdevice, cell phone, internet of things device, personal digitalassistant, mobile computer, wearable device (for example, watch, headmounted display, virtual reality glasses, etc.), tablet, personalcomputer, wireless terminal, laptop computer, or any type of device thathas wireless capabilities. As used herein, a wireless device may be anyportable, or movable device or machine that is configurable to acquirewireless and/or SV signals transmitted from, and transmit wirelesssignals to, one or more wireless communication devices or networks.Thus, by way of example but not limitation, the device 400 may include aradio device, a cellular telephone device, a computing device, apersonal communication system device, or other like movable wirelesscommunication equipped device, appliance, or machine. The term “device”is also intended to include devices which communicate with a personalnavigation device, such as by short-range wireless, infrared, wirelineconnection, or other connection—regardless of whether SV signalreception, assistance data reception, and/or position-related processingoccurs at the device 400. Also, the term “device” is intended to includeall devices, including wireless communication devices, wirelessterminals, cell phones, computers, laptops, etc. which are capable ofcommunication with a server, such as via the Internet, WiFi, or othernetwork, and regardless of whether satellite signal reception,assistance data reception, and/or position-related processing occurs atthe wireless device, at a server, or at another wireless deviceassociated with the network. Any operable combination of the above canalso be considered a “device” as used herein. Other uses may also bepossible. While various examples given in the description below relateto wireless devices, the techniques described herein can be applied toother devices.

The device may communicate wirelessly with a plurality of APs, basestations and/or femtocells using RF signals (for example, 400 MHz, 1900MHz, 2.4 GHz, 4.6 GHz, and 4.9/5.0 GHz bands) and standardized protocolsfor the modulation of the RF signals and the exchanging of information.For example, the protocol may be Institute of Electrical and ElectronicsEngineers (IEEE) 802.11x or 3GPP LTE. By extracting different types ofinformation from the exchanged signals, and utilizing the layout of thenetwork (i.e., the network geometry) the wireless device may determineits position within a predefined reference coordinate system.

It should be appreciated that embodiments of the invention as will behereinafter described may be implemented through the execution ofinstructions, for example as stored in the memory 405 or other element,by processor 401 of device 400 and/or other circuitry of device 400and/or other devices. Particularly, circuitry of device 400, includingbut not limited to processor 401, may operate under the control of aprogram, routine, or the execution of instructions to execute methods orprocesses in accordance with embodiments of the invention. For example,such a program may be implemented in firmware or software (e.g. storedin memory 405 and/or other locations) and may be implemented byprocessors, such as processor 401, and/or other circuitry of device 400.Further, it should be appreciated that the terms processor,microprocessor, circuitry, controller, etc., may refer to any type oflogic or circuitry capable of executing logic, commands, instructions,software, firmware, functionality and the like. Some or all of thefunctions, engines or modules described herein (for example, SVIMfeatures and methods illustrated in at least FIG. 2 and FIG. 3) may beperformed by the device 400 itself (for example, via instructions ofmodule 455 stored in memory 405). For example, device 400 for refining aradio frequency (RF) time of arrival (TOA) may comprise memory 405 andprocessor 401 coupled to the memory. The memory 405 and processor 401may be configured to: obtain one or more satellites in one or moreglobal navigation satellite systems (GNSS) to monitor based on areference crowdsourced integrity report; determine, at the mobiledevice, one or more satellite integrity metrics for the one or moresatellites based at least on signals from the one or more satellites;estimate a position of the mobile device; and provide the position ofthe mobile device and the one or more satellite integrity metrics.

In some embodiments, device 400 provides the means for implementing theSVIM described herein (for example, at least with respect to thefeatures of FIGS. 2 and 3 above). In one embodiment, device 400 is anapparatus to provide means for obtaining one or more satellites in oneor more global navigation satellite systems (GNSS) to monitor based on areference crowdsourced integrity report; means for determining, at themobile device, one or more satellite integrity metrics for the one ormore satellites based at least on signals from the one or moresatellites; means for estimating a position of the mobile device; andmeans for providing the position of the mobile device and the one ormore satellite integrity metrics.

In some embodiments or some or all of the functions, engines or modulesdescribed herein may be performed by another system connected throughI/O controller 425 or network interface 410 (wirelessly or wired) to thedevice. Thus, some and/or all of the functions may be performed byanother system and the results or intermediate calculations may betransferred back to the wireless device. In some embodiments, such otherdevice may comprise a server configured to process information in realtime or near real time. In some embodiments, the other device isconfigured to predetermine the results, for example based on a knownconfiguration of the device. Further, one or more of the elementsillustrated in FIG. 4 may be omitted from the device 400. For example,one or more of the sensors 435 may be omitted in some embodiments.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. Likewise, the term “embodiments”does not require that all embodiments include the discussed feature,advantage or mode of operation.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of embodiments ofthe invention. As used herein, the singular forms “a”, “an” and “the”are intended to include the plural forms as well, unless the contextclearly indicates otherwise. It will be further understood that theterms “comprises”, “comprising”, “includes” and/or “including”, whenused herein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Further, many embodiments are described in terms of sequences of actionsto be performed by, for example, elements of a computing device (forexample, a server or device). It will be recognized that various actionsdescribed herein can be performed by specific circuits (for example,application specific integrated circuits), by program instructions beingexecuted by one or more processors, or by a combination of both.Additionally, these sequence of actions described herein can beconsidered to be embodied entirely within any form of computer readablestorage medium having stored therein a corresponding set of computerinstructions that upon execution would cause an associated processor toperform the functionality described herein. Thus, the various aspects ofthe invention may be embodied in a number of different forms, all ofwhich have been contemplated to be within the scope of the claimedsubject matter. In addition, for each of the embodiments describedherein, the corresponding form of any such embodiments may be describedherein as, for example, “logic configured to” perform the describedaction.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, engines, circuits, and algorithm stepsdescribed in connection with the embodiments disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, engines,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentinvention.

The various illustrative logical blocks, modules, and circuits describedin connection with the embodiments disclosed herein may be implementedor performed with a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, for example, acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The steps of a method or algorithm described in connection with theembodiments disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read only memory (ROM), erasable programmable read-only memory(EPROM), electrically erasable programmable read-only memory (EEPROM),registers, hard disk, a removable disk, a compact disc read only memory(CD-ROM), digital versatile disc (DVD), or any other form of storagemedium known in the art. An exemplary storage medium is coupled to theprocessor such the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium may be integral to the processor. The processor and the storagemedium may reside in an ASIC. The ASIC may reside in a user terminal. Inthe alternative, the processor and the storage medium may reside asdiscrete components in a user terminal.

In one or more exemplary embodiments, the functions or modules describedmay be implemented in hardware, software, firmware, or any combinationthereof. If implemented in software as a computer program product, thefunctions or modules may be stored on or transmitted over as one or moreinstructions or code on a non-transitory computer-readable medium.Computer-readable media can include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media may be anyavailable media that can be accessed by a computer. By way of example,and not limitation, such non-transitory computer-readable media cancomprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage,magnetic disk storage or other magnetic storage devices, or any othermedium that can be used to carry or store desired program code in theform of instructions or data structures and that can be accessed by acomputer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a web site,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of non-transitory computer-readable media.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for a mobile device to monitor satelliteintegrity, the method comprising: obtaining one or more satellites inone or more global navigation satellite systems (GNSS) to monitor basedon a reference crowdsourced integrity report; determining, at the mobiledevice, one or more satellite integrity metrics for the one or moresatellites based at least on signals from the one or more satellites;estimating a position of the mobile device; and providing the positionof the mobile device and the one or more satellite integrity metrics. 2.The method of claim 1, wherein the one or more integrity metricsincludes one or more of: pseudorange metrics between the mobile deviceand the one or more satellites, pseudorange rate metrics between themobile device and the one or more satellites, carrier phase metrics fromthe one or more satellites, signal identifier for the one or moresatellites, signal strength for received satellite signals, navigationmessages from the one or more satellites, determination of satellitesignal integrity, confidence rating the one or more integrity metrics,or any combination thereof.
 3. The method of claim 1, wherein theproviding the position of the mobile device and the one or moresatellite integrity metrics comprises: selecting a subset of the one ormore satellite integrity metrics for the one or more satellites based ona request for particular crowdsourced metrics; and providing theposition of the mobile device and the subset of the one or moresatellite integrity metrics for the one or more satellites.
 4. Themethod of claim 1, wherein the reference crowdsourced integrity reportcomprises one or more of: integrity determination of one or moresatellites, integrity determination of one or more constellations,integrity determination of one or more geographic areas, expectedreliability of each integrity determination, expected signal strength ofa satellite signal, expected accuracy of a satellite signal, time ofapplicability for one or more aspects of the reference crowdsourcedintegrity report, geographic area associated with one or more aspects ofthe reference integrity report, or any combination thereof.
 5. Themethod of claim 1, further comprising: receiving, in response toproviding the position, and the satellite integrity metrics, an updatedcrowdsourced integrity report, the report updated from one or moreaspects of the provided satellite integrity metrics.
 6. The method ofclaim 1, wherein the estimated position of the mobile device isdetermined at least in part on a GNSS based position, and wherein theGNSS based position is determined at least in part on the referencecrowdsourced integrity report.
 7. The method of claim 1, wherein theobtaining the one or more satellites in the one or more globalnavigation satellite systems (GNSS) to monitor comprises: obtainingsatellites currently detected by the mobile device that are missing fromthe reference crowdsourced integrity report.
 8. A device to monitorsatellite integrity, the device comprising: memory; and a processorcoupled to the memory and the processor configured to: obtain one ormore satellites in one or more global navigation satellite systems(GNSS) to monitor based on a reference crowdsourced integrity report;determine, at the mobile device, one or more satellite integrity metricsfor the one or more satellites based at least on signals from the one ormore satellites; estimate a position of the mobile device; and providethe position of the mobile device and the one or more satelliteintegrity metrics.
 9. The device of claim 8, wherein the one or moreintegrity metrics includes one or more of: pseudorange metrics betweenthe mobile device and the one or more satellites, pseudorange ratemetrics between the mobile device and the one or more satellites,carrier phase metrics from the one or more satellites, signal identifierfor the one or more satellites, signal strength for received satellitesignals, navigation messages from the one or more satellites,determination of satellite signal integrity, confidence rating the oneor more integrity metrics, or any combination thereof.
 10. The device ofclaim 8, wherein the processor configured to provide the position of themobile device and the one or more satellite integrity metrics is furtherconfigured to: select a subset of the one or more satellite integritymetrics for the one or more satellites based on a request for particularcrowdsourced metrics; and provide the position of the mobile device andthe subset of the one or more satellite integrity metrics for the one ormore satellites.
 11. The device of claim 8, wherein the referencecrowdsourced integrity report comprises one or more of: integritydetermination of one or more satellites, integrity determination of oneor more constellations, integrity determination of one or moregeographic areas, expected reliability of each integrity determination,expected signal strength of a satellite signal, expected accuracy of asatellite signal, time of applicability for one or more aspects of thereference crowdsourced integrity report, geographic area associated withone or more aspects of the reference integrity report, or anycombination thereof.
 12. The device of claim 8, wherein the processor isfurther configured to: receive, in response to providing the position,and the satellite integrity metrics, an updated crowdsourced integrityreport, the report updated from one or more aspects of the providedsatellite integrity metrics.
 13. The device of claim 8, wherein theestimated position of the mobile device is determined at least in parton a GNSS based position, and wherein the GNSS based position isdetermined at least in part on the reference crowdsourced integrityreport.
 14. The device of claim 8, wherein the processor configured toobtain the one or more satellites in the one or more global navigationsatellite systems (GNSS) to monitor is further configured to: obtainsatellites currently detected by the mobile device that are missing fromthe reference crowdsourced integrity report.
 15. A machine readablenon-transitory storage medium having stored therein program instructionsthat are executable by a processor to: obtain one or more satellites inone or more global navigation satellite systems (GNSS) to monitor basedon a reference crowdsourced integrity report; determine, at the mobiledevice, one or more satellite integrity metrics for the one or moresatellites based at least on signals from the one or more satellites;estimate a position of the mobile device; and provide the position ofthe mobile device and the one or more satellite integrity metrics. 16.The medium of claim 15, wherein the one or more integrity metricsincludes one or more of: pseudorange metrics between the mobile deviceand the one or more satellites, pseudorange rate metrics between themobile device and the one or more satellites, carrier phase metrics fromthe one or more satellites, signal identifier for the one or moresatellites, signal strength for received satellite signals, navigationmessages from the one or more satellites, determination of satellitesignal integrity, confidence rating the one or more integrity metrics,or any combination thereof.
 17. The medium of claim 15, wherein theinstructions to provide the position of the mobile device and the one ormore satellite integrity metrics comprises: select a subset of the oneor more satellite integrity metrics for the one or more satellites basedon a request for particular crowdsourced metrics; and provide theposition of the mobile device and the subset of the one or moresatellite integrity metrics for the one or more satellites.
 18. Themedium of claim 15, wherein the reference crowdsourced integrity reportcomprises one or more of: integrity determination of one or moresatellites, integrity determination of one or more constellations,integrity determination of one or more geographic areas, expectedreliability of each integrity determination, expected signal strength ofa satellite signal, expected accuracy of a satellite signal, time ofapplicability for one or more aspects of the reference crowdsourcedintegrity report, geographic area associated with one or more aspects ofthe reference integrity report, or any combination thereof.
 19. Themedium of claim 15, further comprising: receive, in response toproviding the position, and the satellite integrity metrics, an updatedcrowdsourced integrity report, the report updated from one or moreaspects of the provided satellite integrity metrics.
 20. The medium ofclaim 15, wherein the estimated position of the mobile device isdetermined at least in part on a GNSS based position, and wherein theGNSS based position is determined at least in part on the referencecrowdsourced integrity report.
 21. The medium of claim 15, wherein theinstructions to obtain the one or more satellites in the one or moreglobal navigation satellite systems (GNSS) to monitor comprisesinstructions to: obtain satellites currently detected by the mobiledevice that are missing from the reference crowdsourced integrityreport.
 22. An apparatus to verify satellite integrity, the apparatuscomprising: means for obtaining one or more satellites in one or moreglobal navigation satellite systems (GNSS) to monitor based on areference crowdsourced integrity report; means for determining, at themobile device, one or more satellite integrity metrics for the one ormore satellites based at least on signals from the one or moresatellites; means for estimating a position of the mobile device; andmeans for providing the position of the mobile device and the one ormore satellite integrity metrics.
 23. The apparatus of claim 22, whereinthe one or more integrity metrics includes one or more of: pseudorangemetrics between the mobile device and the one or more satellites,pseudorange rate metrics between the mobile device and the one or moresatellites, carrier phase metrics from the one or more satellites,signal identifier for the one or more satellites, signal strength forreceived satellite signals, navigation messages from the one or moresatellites, determination of satellite signal integrity, confidencerating the one or more integrity metrics, or any combination thereof.24. The apparatus of claim 22, wherein the means for providing theposition of the mobile device and the one or more satellite integritymetrics comprises: means for selecting a subset of the one or moresatellite integrity metrics for the one or more satellites based on arequest for particular crowdsourced metrics; and means for providing theposition of the mobile device and the subset of the one or moresatellite integrity metrics for the one or more satellites.
 25. Theapparatus of claim 22, wherein the reference crowdsourced integrityreport comprises one or more of: integrity determination of one or moresatellites, integrity determination of one or more constellations,integrity determination of one or more geographic areas, expectedreliability of each integrity determination, expected signal strength ofa satellite signal, expected accuracy of a satellite signal, time ofapplicability for one or more aspects of the reference crowdsourcedintegrity report, geographic area associated with one or more aspects ofthe reference integrity report, or any combination thereof.
 26. Theapparatus of claim 22, further comprising: means for receiving, inresponse to providing the position, and the satellite integrity metrics,an updated crowdsourced integrity report, the report updated from one ormore aspects of the provided satellite integrity metrics.
 27. Theapparatus of claim 22, wherein the estimated position of the mobiledevice is determined at least in part on a GNSS based position, andwherein the GNSS based position is determined at least in part on thereference crowdsourced integrity report.
 28. The apparatus of claim 22,wherein the means for obtaining the one or more satellites in the one ormore global navigation satellite systems (GNSS) to monitor comprises:means for obtaining satellites currently detected by the mobile devicethat are missing from the reference crowdsourced integrity report.